Fix compilation with freepascal

This pull request fixes compilation with Lazarus and fpc 2.6.4. Currently it compiles and works only in Windows since some units depend heavily on win api. The sources changes are small and i took care to avoid breaking Delphi compilation, but since i don't have access to Delphi i cannot test.

Changes:
- Remove buggy and unnecessary GetMem custom implementation
- Wrap Delphi specific code in defines
- Adapt packages to avoid path conflicts and to properly compile as needed
- Merge JclContainers package into Fcl since there's a circular dependency between both
- Update gitignore to match fpc / Lazarus created files
- Include ini file by default. The jcl install script is not necessary at all for Lazarus / fpc
- Adapt ExprEval example to Lazarus